
Toothbrushes are often worn enough to be replaced before they look worn, and worn and fractured bristles are a breeding ground for germs, fungus and bacteria. Also, worn toothbrushes can damage gum tissues. However, if you have gum disease, you should change your toothbrush every 4 - 6 weeks because bacteria can harbor in the bristles. A new toothbrush is 30% more effective at removing plaque.